MECHANICAL FUEL PUMP With the change to negative earth electrical system in October 1969, the electrical type fuel pump was replaced by a mechanical one, mounted on the engine at the rear and driven by an eccentric on the camshaft. Most models will be fitted with the 700 series type pump which has a detachable domed cover for access to the fuel filter screen. However, some later models are fitted with the 800 series type which is a sealed unit and in this case no maintenance or overhaul is possible.
The mechanical pump installation is shown in , but removal is a difficult task while the engine is installed in the car and it will be necessary to remove the surrounding components to gain access to the unit. On some models it is difficult even to find enough room to remove the top cover to allow the filter screen to be cleaned. When refitting the pump, always ensure that the total thickness of the pump insulating block with its two gaskets remains unaltered .
The main sources of trouble with the mechanical type pump are the fuel valves and the diaphragm, but as stated above these can be serviced only on the 700 series pump.